Space telegraphy.



No. 767,996.- PATENTED AUG. 16, 190

J. S. STONE.

SPACE TELEGRAPHY.

APPLIOATIYON IILED- FEB. 15. 1904.

N0 J HODEL.

I ll/I/I/II/ WITHEEEE: I Q IHJEIJT'UR:

' yremmu'sm I ,a auflfimm No. 767,996. a

, 'UNITED STATES- Patented August 16, 1904.

PATENT OFFICE.

JOHNSTONE STONE, OE CAMBRIDGE, MASSACHUSETTS, ASSIGNOE To WILLIAM w. SWAN, TRUSTEE, or BROOKLINE, MASSACHUSETTS.

SPACE TELEGRAPHY.

SPECIFICATION forming part of Letters Patent No. 767,996, dated August 16, 1904.

,' l Application filed February 15, 1904. Serial No. 198,591. (No model.)

To all whom it may concern.-

Be it known that 1, JOHN STONE STONE, a

citizen of the United States, and a resident of Cambridge, in the county of Middlesex and State of Massachusetts, have invented a certain new and useful Improvement in Space Telegraphy, of which the following is a specification.

This invention relates to space or wireless telegraphy by electromagnetic waves in the form ofelectroradiant energy; and it relates more particularly to electroreceptive or electric translating devices adapted to utilize in their operation the dissipative energy of the electrical oscillations or oscillatory electric currents developed by electromagnetic waves in the circuits in which such devices are included. Electrorec'eptive devices of such character have long been known for detecting and measuring the energy of electromagnetic waves, and they are generally known as bolometers? In my application Serial No. 119,211, filed August 11, 1902, I

have described the application of such electroreceptive devices to selective electric signaling and have therein claimed the same broadly. In my application Serial No. 182,628, filed November 25, 1903, I have'described and claimed a specific form of such electroreceptive device and a particular form of space-telegraph receiving system in which the same may be employed. In said applications I have pointed out that in orderto be rapidlyresponsive to changes in thermal conditionc'. 6., in order to be sensitivethe fine wires or strips of such bolometers should be of small thermal time constant compared to the thermal time constants of the bolometers heretofore used for experimental purposes and that in order to be of such Small thermal time constant the fine wires or strips should be of small masst'. a, of small length and small sectionshouldbe of a material of low specific heat, and that the heat insulation of the fine wires or strips should be not too perfect. I have also pointed out that for greater efficiency the bolometer fine wires or strips should be of highresistance temperature coefiicient and of high specific resistance. I

have also shown that as the oscillatory electric currents developed in the receiving-conductors of space-telegraph systems are of small amplitude it is necessary to employ some means whereby the currents developed in the receiving system by electromagnetic waves may be amplified in order that an. appreciable amount of energy may be dissipated in the bolometer wire or strip without making the latter of excessively high resistance. For amplifying the currents developed in the receiving system by electromagnetic waves of a definite predetermined frequency I have described a resonant circuit or a group of resonant circuits attuned to such frequency. The resonant circuits strongly oppose the development therein of currents of frequencies different from that to which they are attuned, so that by means of Such resonant circuits the bolometer fine wires or strips are protected from extraneous electrical forces which might otherwise destroy them.

The present invention may be best understood by having reference to the drawings which accompany and form a part of this specification and which illustrate one embodiment of an improved form of electroreceptive device produced by the method described and claimed in my application Serial No. 193,592, filed simultaneously herewith.

In the drawings, Figures 1 and 2 illustrate, respectively, the first and second stages in the formation of the bolometer herein described, and Fig. 3 represents the completed bolometer and its accessory apparatus connected in a Space-telegraph receiving system.

' In the figures, W represents a short length of wire known as Wollaston wire, greatly magnified. The method devised by Dr. VVollaston for producing this Wire consists in incasing a fine platinum wire in silver, reducing the composite wire so formed, and then dissolving away the silver casing with warm nitrous acid. In this way wire of diameter as small as one fifty-thousandth of an inch was produced, as fully set forth in the Encyclopceaha Britannica in an article entitled 1N ire, to which all those wishing to practice my invention are referred for further details concerning the manufacture of wire suitable for use in the bolometer herein described, although such wire has long been in commercial use i and consequently the desired smallmass,in virtue of which the temperature of such fine wire may be appreciably elevated by small amounts of energy, is as follows: The Vollaston wire is immersed to any desired depth in a bath of mercury or mercury alloy 3, contained in a vessel 3, such as an iron thimble. Inasmuch as mercury wets silver, the meniscus formed with the silver coating 1 of the platinum wire 2 is concave, as shown at a. This, as is well understood, is caused by capillary attraction and by the adhesion of the mercury to the sil ver. hen mercury does not wet a metal '2. 0., when the metal is not soluble in mercury-the meniscus is convex, as shown at 5, where the mercury contacts the walls of the iron thimble. The effect of the mercury or the mercury alloy on the silver coating of the platinum wire is to form an amalgam there with-zl a, to dissolve the silver away from the platinum wire-thus exposing the platinum wire from the upper end of the concave meniscus 4 in Fig 1 to the lower end of the convex meniscus 4 in Fig. 2, formed by the mercury in contact with the platinum wire 2. It is a fact that mercury does not wet platinum 0., does not dissolve it-so that its meniscus therewith is convex, as shown at t, Fig. 2, and it is also a fact that platinum has a greater specific gravity than mercury, so that the fine platinum wire is not forced out of the mercury. The length of the platinum wire from which the silver casing has been dissolved by the process above described and which is thereby rendered effective as a bolometer fine wire is very short indeed, being, in fact, equal approximately to the sum of the lengths of the concave meniscus 4 and the convex meniscus 4.

Although I have specially referred to ollaston wire in this specification as a desirable means for obtaining the electrical conductor ment of this invention.

l l l mercury alloy. Gold possesses these characteristics. and therefore a composite wire formed of gold incased in silver or other ductile metal soluble in n'iercury or mercury alloy may be employed.

In Fig. 3 is shown a practicable embodi- In this ligure II is a frame supporting an iron thimble 3 or other vessel of a material not soluble in mercury containing mercury or an alley or amalgam thereof 3. 9 is a screw threaded into the thimble 3', whereby the level of the mercury in the thimble may be elevated or depressed. 10 is a flat spring rigidly attached to the frame H at point 11 and bearingupwardly at its extreme end upon the flange of a micrometerscrew 12, threading into the base lrl, whereby the spring 10 may be depressed or elevated without lost motion. 6 is a glass tube rigidly attached to the spring 10 and containing a length of Vollaston wire \V in its silver jacket. 7 is a stopper by which the \Yollaston wire is sealed into the upper end of the tube. The tube 6 is desirable to protect the bolometer -wire from terrestrial vibration. 8 8 are conductors by which the bolometer fine wire or strip is connected in the resonant circuit (.l 8 8 L 12. M is a step-down transformer by which said resonant circuit is associated with the elevated conductor V. I1 and 1:. are respectively the primary and secondary windings of transformer M. R is a resistance, B is a battery, and T is a signalindicating device, in'eferably a telephone-receiver, connected across the bolometer-wire, and L L are choking-coils connected between the bolometer and the signalindicating device T.

After the silver casing has been dissolved from the platinum wire, as above described, the length, and consequently the mass, of the platinum wire may be still further reduced by means of the micrometer-screw [2. The relative position of the screw 12 and the wire V with respect to the point of application of the spring 10 to the frame l'l permits an exceedingly fine adjustment of the length, and consequently the mass, of the bolometer line wire, as the movement of the wire may by these means be made any desired fraction of the translational movement of the screw.

1 do not wish to be limited to the form of apparatus herein described, as it is obvious that many changesmay be made therein without dt-iparting from the spirit of my invention. For example, the 1nicrometer-screw may be operatively connected with the vessel containing the mercury, so that the adjustment of the mass of the bolometer line wire or strip may be made without moving the wire or strip, but by moving the mercury with respect to said wire or strip. \Yhile I have herein specifically referred to the screws 12 as a micrometer-screw, I desire it to be understood as meaning thereby any screw of small pitch forms of spring which will accomplish this result.- e

I claim 1. A receiving apparatus for space-telegraph signals comprising a platinum wire or strip of small mass, a casing of silver surrounding one end of said Wire or strip and a mass of mercury or mercury alloy making electrical contact with the other end of said wire or strip.

, 2. A receiving apparatus for space-telegraph signals comprising a wire or strip of small mass and of a metal insoluble in mercury or mercury alloy, a casing of a metal soluble in'rnercury or mercury alloy surround- .ing one end of said wire or strip and a mass of mercury or mercury alloy making electrical contact withthe other end of said wire or strip. i 1

3. A receiving apparatus for space-telegraph signals comprising a platinum wire or strip, of small mass, a casing of silver surrounding one end, of saidwire or strip, a mass of mercury or mercury alloy making elec-= trical contact with the other end of said wire strip of small mass, a .casing of silver surrounding one end of said wire or strip, a mass of' mercury or mercury alloymaking electrical contact with the otherend-of said wire or strip and means for effecting a relative -movement between the wire :or strip and the mercury or mercury alloy;

5. A receiving apparatus forspace-telegraph signals comprising a wire ,or strip of small mass and of a metal insoluble in mercury or. mercury alloy, a casing of a metal soluble inmercury or mercury alloy surroundlng one end or said W1re or strip, a mass of mercury or mercury alloy maklng velectrical contact with the other end of said wire or.

strip, and amicrometer-screw operatively connected to the wire or strip whereby the wire or strip may be moved with respect to the mass of mercury or mercury alloy.

6. A receiving apparatus for space-telegraph signals comprising a Wire or strip of small mass and of a metal insoluble in mer-' cury or-mereury alloy, a casing of a metal soluble in mercury or mercury alloy surrounding one end or sald wire or strip, a mass of mercury ormercury alloy makmg electrical contact with the other end of saidwire or strip and means for effecting a relative movement between the wire or strip and the mercury or mercury alloy.

7 A receiving apparatus for space-telegraph signals comprising a vessel containing a conducting liquid, a wire or strip of small mass and of a metal insoluble in said liquid making electrical contact with said liquid, a

casing of metal soluble in said liquid surrounding said wire or strip, means for conveying electrical oscillations to said wire or strip wherebyits normal temperature may be varied, and a micrometer-screw for effecting a relative movement between the wire or strip and the liquid.

8. A receiving apparatus for space-telegraph signals comprising a metallic Wire or strip of small mass adapted to be heated by the dissipative energy of the electrical oscillations passing therethrough, a bath of conducting liquid making electrical contact therewith, and a micrometer-screw for effecting a relative movement between the wire or strip and the liquid. r

9. A receiving apparatus for space-telegraph'signals comprising a metallic wire or strip of small mass a bath of conducting liquid making electrical contact therewith, a micrometer-screw for effecting a relative movement between the Wire or strip and the liquid, and means for overcoming the lost motion of said micrometerscrew.

10. A receiving apparatus for space-telegraph signals' comprising a metallic wire or strip of small mass, adapted to be heated by the dissipative'energy of the electrical oscillations passing therethrough, a bath of con wire or strip with respect to said liquid.

11. A receiving apparatus for space-telegraph signals comprising a metallic wire or strip of small mass a bath of conducting liquid making electrical contact therewith, a micrometer-screw and means for utilizing a fraction of the translationalmovement of said screw to produce a relative movement between the wire or strip and the liquid.

12. A receiving apparatus for space-telegraph signals comprizing a metallic wire or strip of small mass, a bath of conducting liquid making electrical contact therewith, a micrometer-screw operatively connected to said wire or strip and means for communieating a fraction of the translational movement of said screw to the wire or strip.

13. A receiving apparatus for space-telegraph signals comprising a spring rigidly supported at one'end, a metallic Wire or strip of small mass connected to said spring at'a point intermediate the ends thereof, a bath of conducting liquid making contact with may be immersed in said mercury or mercury said wire or strip and a micrometer-screw for moving the unsupported end of said spring.

14. A receiving apparatus for space-telegraph signals comprising a metallic wire or strip of small mass, a bath of conducting liquid making electrical contact therewith, a micrometer-screw for moving said wire or strip with respect to the bath of conducting liquid and means for overcoming the lost motion of said micrometer-screw.

15. A receiving apparatus for space-telegraph signals comprising a platinum wire or strip of small mass incased in silver, a vessel containing mercury or mercury alloy and means whereby the lower end of said wire or strip may be immersed in said mercury or mercury alloy.

16. A receiving apparatus for space-telegraph signals comprising a vessel containing a conducting liquid, a wire or strip of small mass and of a material not soluble in said liquid, means for conveying electrical oscillations to said wire or strip whereby its dissipative resistance may be varied, a casing of a material soluble in said liquid surrounding said wire or strip and a micrometer-screw operatively connected to said wire or strip whereby the latter may be immersed in said liquid.

17. A receiving apparatus for space-telegraph signals comprising a platinum wire or strip of small mass incased in silver, a vessel containing mercury or mercury alloy, means whereby the lower end of said wire or strip alloy and means for regulating the level of the mercury or mercury alloy in the vessel.

'18. A receiving apparatus for space-telegraph signals comprising a vessel containing a conducting liquid, a wire or strip of small mass and of a material not soluble in said liquid, a casing of a material soluble in said liquid surrounding saidwire or strip, a micrometer-screw operatively connected to said wire or strip whereby the latter may be immersed in said liquid and means for regulating the level of the liquid in the vessel.

19. In a space-telegraph receiving system, an elevated conductor and a resonant circuit associated therewith, in combination with a receiving apparatus for space-telegraph signals comprising a vessel containing a conducting liquid, a wire or strip of small mass and of a metal insoluble in said liquid making electrical contact with said liquid and a casing of ametal solublein said liquid surrounding said wire or strip.

20. In a space-telegraph receiving system, an elevated conductor and a resonant circuit associated therewith by means of a step-down transformer, in combination with a receiving apparatus for space-telegraph signals comprising a vessel containing a conducting liquid, a wire or strip of small mass and of a metal insoluble in said liquid making electrical contact with said liq uid, and a casing of a metal soluble in said liquid surrounding said wire or strip.

21. In a space-telegraph receiving system, a circuit attuned by capacity and inductance to the frequency of the waves the energy of which is to be received, in combination with a receiving apparatus for space-telegraph signals adapted to utilize in its operation the dissipative energy of the electrical oscillations developed by electromagnetic signal-waves in the receiving system and comprising a wire or strip of small mass immersed in a conducting liquid.

22. A receiving apparatus for space-telegraph signals comprising a metallic wire or strip of small mass, a bath of conducting liquid making electrical contact therewith, and a tube surrounding said wire or strip to protect the. same from vibration.

.28. A receiving apparatus for space-telegraph signals comprising a metallic wire or strip of small mass, a bath of conducting liquid making electrical contact therewith, and means for protecting said wire or strip from vibration.

24:. A receiving apparatus for space-telegraph signals comprising a metallic wire or strip of small mass immersed in abath of conducting liquid, and a tube surrounding said wire or strip and also immersed in said conducting liquid to protect said wire or strip from vibration.

25. In a receiving apparatus for space-tele graph signals, the combination with a bolom eter wire or strip having one end immersed in a conducting liquid, of means for varying the extent of such immersion.

In testimony whereof I have hereunto subscribed my name this llth day of February, 190 i.

JOHN STONE STONE.

itnesses:

BRAINERD T. JUDKINS, Gr. ADELAIDE HreGINs.

It is hereby certified thatin Letters Patent N o. 767 ,996, granted August 16, 1904, upon the application of John Stone Stone, of Cambridge, Massachusetts, for an improvement in Space Telegraphy, errors appear in the printed specification requiring correction, as follows: In line 128, page 2, the word screws should read screw and 'in line 116; page 3, the word comprizing shou1d read comprising; and that the said.

Letters Patent should be read with this correction therein that the same may conform to the record of thecase in the Patent Office.

Signed and sealed this 4th day of July, A. D., 1905.

S g F. I. ALLEN,

Commissioner 7 of Patents. 

